Impact of Ocular Residual Astigmatism on Visual and Refractive Outcomes Following Photorefractive Keratectomy.

BACKGROUND

The aim of the study was to evaluate the impact of ocular residual astigmatism (ORA) on refractive and visual outcomes following photorefractive keratectomy (PRK) in myopic astigmatism patients.

MATERIALS AND

METHODS

This analytical cross-sectional study was performed on patients who underwent PRK. Patients were evaluated for refractive error, visual acuity, and keratometry before and six months after surgery. To calculate the ORA, vectorial differences between corneal plane refractive astigmatism and keratometric astigmatism were established.

RESULTS

Two hundred and six eyes from 206 patients including 117 females (56.8%), with a mean age of 32.32 ± 7.03 years were enrolled. The mean ORA was 0.79 ± 0.35 D. There was a negative correlation between cylinder magnitude (r = -0.24, P = 0.002), percentage of success of astigmatism surgery (r = -0.17, P = 0.01), and ORA. Patients with against-the-rule (ATR) astigmatism had high ORA (P = 0.01). The mean age was higher in patients with a high ORA; however, these differences did not reach a significant level (P = 0.07).

CONCLUSION

We found comparable visual outcomes between eyes with low and high ORA that were treated with PRK. Patients with ATR astigmatism had more ORA and the success of astigmatism surgery was lower in patients with a higher ORA.